Telescoping sea floor soil sampler

ABSTRACT

A deep penetrating ocean bottom soil sampler employing a plurality of telescoping tubes that may be sequentially driven downwardly to penetrate the ocean floor a distance equal to approximately 1/2 of the cumulative length of the tubes. As the sampler with extended tubes is withdrawn, it extracts an elongate core comprising a representative ocean bottom soil sample.

United States Patent Gill 1541 TELESCOPING SEA FLOOR SOIL SAMPLER [72] Inventor: Henry L. Gill, Ojai, Calif.

[73] Assignee: The United States of America as represented by the Secretary of the Navy [22] Filed: Dec. 14, 1970 [21] Appl. No.: 97,827

Related U.S. Application Data [62] Division of Ser No. 813,403, Apr. 1, 1969, Pat. No.

[52] US. Cl ..175/6, 175/20 [51] ...E2lb 7/12, 1321b 49/02 [58] Field of Search ..175/58, 20, 6, 7, 57, 405; 61/727; 166/50 [56] References Cited UNITED STATES PATENTS 1,896,469 2/1933 Soll 175/249 x [4 1 June6,1972

3,098,533 7/1963 Ostrom ..l75/6 3,295,616 1/1967 Charlton 175/58 X 3,438,452 4/1969 Bernard et a1. 175/58 X 3,477,525 11/1969 Farrell et al ..l75/6 X 3,585,738 6/1971 Koning 1 75/6 X Primary ExaminerDavid H. Brown 7 Attorney-Richard S. Sciascia, Q. Baxter Warner and Gayward N. Mann [57] ABSTRACT A deep penetrating ocean bottom soil sampler employing a v plurality of telescoping tubes that may be sequentially driven downwardly to penetrate the ocean floor a distance equal to approximately 96 of the cumulative length of the tubes. As the sampler with extended tubes is withdrawn, it extracts an elongate core comprising a representative ocean bottom soil sample.

5 Claims, 7 Drawing Figures PATENTEDJUN 6 I972 SHEET 1 or 2 HENRY L. GILL INVENTOR Q75 FIG. 4

ATTORNEY PATENTEUJUN 8 I972 SHEET 2 BF 2 FIG. 5

FIG.6

TELESCOPING SEA FLOOR SOIL SAMPLER CROSS-REFERENCE TO RELATED APPLICATION This application is a division of application Ser. No. 813,403, now U.S. Pat. No. 3,576,220, filed 1 Apr. 1969.

STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to soil sampling devices and more particularly to deep penetrating soil samplers employed in obtaining relatively undisturbed ocean bottom samples.

2. Description of the Prior Art It is suspected that much of the shear strength information that has been published on sea floor soils may be in error because of sample deformation. This is particularly true for deep penetrating soil samples in which the sampling equipment is nonnally designed to obtain long cores having a fairly large length to diameter ratio.

Previously the length of a soil sample and therefore the penetration depth of the sampling tube has been limited by the amount of sample disturbance or deformation which results from frictional contact and scraping between the outside surface of the sample core and the inside surface of the long sampling tube. Such deformation has heretofore effectively limited the length of the sample and therefore the depth from which a satisfactory, relatively undisturbed sample could be obtained.

SUMMARY OF THE INVENTION The present invention comprises an ocean bottom soil sampler in which a plurality of telescoping tubes are sequentially driven into the ocean floor. As the tube assembly is withdrawn, it carries therein a representative ocean bottom soil sample which is relatively undisturbed and, therefore, satisfactory for shear strength and other soil tests.

STATEMENT OF THE OBJECTS OF THE INVENTION An object of the present invention is to provide apparatus for obtaining ocean floor soil samples.

Another object of the present invention is to provide a relatively compact apparatus capable of obtaining long core ocean floor soil samples, but wherein the core material is relatively undisturbed.

Another object is to provide an improved method of isolating a sample core from the surrounding soil material in progressive steps by the use of interconnected coaxial tubes so that the outer surfaces of adjacent core sections are not disturbed by the passage thereover of a single sampling tube.

Another object of the present invention is to provide a reliable method and apparatus for retrieving ocean bottom soil samples.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical side elevational view of a sampler assembly ready for insertion into the ocean floor with tubes ex- FIG. 4 is a transverse sectional view taken on a line substantially corresponding to line 4-4 of FIG. 3.

FIG. 5 is a diagrammatic view of portions of three separate tubes showing how each tube and the tube interconnecting clips thereon are attached by tripping straps or cables to the next smaller tube.

FIG. 6 is a view similar to that of FIG. 5 in which the straps or cables are in a taut position with the clip tripped and the outer tube free to pass downwardly.

FIG. 7 is an enlarged view of the tube interconnecting clip shown in FIGS. 5 and 6.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, there is shown the soil sampler assembly of this invention in its normal extended tube condition ready to be dropped to the ocean bottom. As there shown the entire assembly is suspended from a cable 68 which passes through a vaned stabilizing ring or shroud assembly 70 and down through the hollow center of an elongate stabilizing fin assembly supporting boom 71. It will be noted that the sampler assembly comprises a number of extended tubes ranging from the small innermost tube 50 at the bottom (FIG. 1) through successively larger tubes 52, 54, 56 and 58 and terminating in a much longer outer tube 60. As shown the cable 68, after passing through the boom 71 and the extended tubes 52 to 60, is fastened at its lower end by any suitable anchor means such as fitting 69, to a cross member 51 extending across the upper end of tube 50.

A housing 64, spaced a short distance above the upper end of the elongate outer tube 60 by brackets 63, may contain a heavy weight, or it may enclose a power driven mechanism of the pile driver or other type designed to impart a downward thrust to the large tube 60 and the interconnected assembly of smaller tubes. It will be apparent that the power means employed may include shifting weights which have a pile driver action, a propeller drive means whereby downward thrust is obtained by forcing the surrounding water upwardly, or reaction force may be generated through propellant gases exhausting upwardly from nozzles 66 in a manner well known in connection with jet thrust action or underwater vehicles.

The device of this invention may be released for free-fall" descent to the deep ocean floor or it may remain tethered to a support cable 68 which is then payed out from the surface ship or platform. When the extended telescoping tube arrangement of FIG. 1 reaches the ocean floor the successive tubes are compacted into each other so that tube 50, after entering the soil and surrounding the top portion of the core sample, comes to rest with its upper end cross member 51 resting on the top end of the soil sample. At this point shear pins 53, of relatively low strength resistance, sever and permit the next outer tube 52 to slide downwardly over the surface of tube 50 (FIG. 3).

Tubes 50 and 52 are secured together in extended relationship as shown in FIG. 1 by shear pins 53, several of which may be employed for the purpose. Two such pins are indicated in FIG. 1 and in the detailed showing of FIG. 3 an inboard end fragment of a fractured pin 53 is shown penetrating the upper end of tube 50 and received in a recess in cross member 51.

It will be noted that the remaining tubes 52 to 58 each have a strap or cable interconnecting means of the type illustrated in detail in FIGS. 5-7. As there shown, a cable 44 is attached at one end to the top of tube 52 at point 46 and at the other end to the end of a link 43 of clip 40 recessed in a slotted opening 41 in the next larger tube. The attachment at point 46 may be made in the form of a readily detachable fastener to facilitate core removal.

The interconnect clip 40 may comprise an upper link 43 and a lower link 45, the latter resting against an elevated abutment 47 located in the lower part of the slot to retain the links in the cocked outwardly directed position when cable 44 is not taut. In the cocked position the bottom edge of the next larger tube 54 engages the upper-surface of link 43 at point 30 while the undersurface of link 43 rests upon an abutment 49 forming a part of link 45. It will be noted that as tube 52 moves downwardly the cable 44 becomes taut, thereby straightening the clip links and allowing the larger tube to move downwardly over the tripped clip as illustrated in FIG. 6. Since each larger diameter tube 52 to 60 will successively be driven into place past the next smaller tube element it will be further forced into the soil until ultimately the large outer tube 60, responding to downward force from whatever power source is employed, fully encloses the now reversely arranged assemblage of telescoped tubes and comes to rest in the fully buried position shown in FIG. 2. It will be noted that in this Figure the interfitting arrangement of associated tubes, together with the interconnecting means of FIGS. -7, has caused each successive tube to enclose only its associated portion of the complete soil sample.

FIG. 3 shows enlarged details of the center portion of FIGS. 1 and 2. As shown the large outer tube 60 has an end piece or cross piece 61 which is shown in the form of a disk and may be provided with a series of open passages 62 through which water entrapped in the sampler may be vented.

Brackets 63 support centrally apertured housing 64 spaced a distance above the top surface of disk 61. This container has a central passage 76 through which passes hollow boom shaft 71 threaded at its lower end into the cross member 61 located at the upper end of tube 60. Through the hollow shaft 71 passes the suspension cable 68 which terminates in cable anchor fitting 69 threaded into the cross member 51 of the smallest tube 50. With the arrangement just described it will be apparent that upward movement of the cable 68 lifts cross member 51 and all the elements thereabove.

Instead of containing a weight, housing 64 may mount any suitable power means for driving the entire assembly downwardly in the event that the weight of the device and the momentum acquired during its fall is not sufficient to cause full sampler penetration when it strikes the ocean floor. For this purpose the housing may house a vertically reciprocable mass to give a pile-driver effect to the whole sampler in a manner well known in the art. This mass may be operated by a self-contained energy source or by electrical or other energy received through the suspension cable 68 or through other cable or hose assemblies. As another form of propulsion a propeller arrangement may be employed which may also be so powered. Also, reaction from exhaust of an underwater propellant, discharged upwardly through nozzles 66 may be used to force the soil sampler tubes down into the ocean bottom.

From the foregoing it will be apparent that through the use of a plurality of telescoping tube sections, each section enclosing and protecting that portion of the sample core contained therein, it is possible to obtain relatively undisturbed samples at great depth, the total undisturbed sample length being merely a matter of the number of telescoping tube sections utilized in the sampling apparatus. For example with a conventional sampling tube 30 feet long the enclosed core sample material at the top has been subjected to the rubbing, scraping and distorting influence of the passage thereabout of some 30 feet of sampling tube. In view of the relatively small diameter of a core sample it has heretofore been virtually impossible to avoid disturbance of the sample even in the very center portion of the core.

With the device of the present invention and employing tube sections about 5 feet long it will be apparent that each successive core sample portion at 5 foot intervals would be enclosed within a separate slightly larger section of tubing. Once so enclosed, that portion of the sample is protected and the next tube section will not touch, scrape or disturb the exterior of the core sample since such next tube section passes over the exterior surface of its adjacent inner tube and therefore cannot disturb the sample surface. When the entire sampling assembly with telescoping tubes is fully extended and has encapsulated a complete core it may then be withdrawn from the ocean floor and lifted to the surface. During this handling each 5 foot length of the core is fully protected by its separate, relatively short, section of tube.

If desired the long tube 60 may be made up of two or more sections such as 60a and 60b, which when fitted together end to end may be joined by any suitable junction means at point 600. Also, the tail fin shroud supporting boom 71 may similarly be made up of two or more sections 71a and 71b which are joined by a coupling fixture 71c of any suitable type. Both of these parts may thus readily be separated into shorter sections if desired in order to facilitate storage and transport.

It will be apparent that once out of the water the process of extracting the core sample is simple and ensures that the sampie is not damaged. One method of core removal is to withdraw outer tube 60, which has no physical contact with the core, and thereafter the appropriate cable 44 is disconnected so that the tube 58 may be slipped upwardly or downwardly off of the lower end of the core. When this has been done the portion of the core previously enclosed by tube 58 is exposed. This may be slid upwardly over the next smaller tube 56 or the core may be severed near the lower end of tube 56 and removed. Thereafter the cable 44 connected to tube 56 may be detached and that tube in turn may be slipped off of its enclosed core portion. This process may be repeated on tubes 54, 52 and 50 until the entire core specimen has been exposed.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A deep penetrating soil sampling device comprising:

an elongate outer tube having a hollow interior;

a plurality of shorter and smaller tubes within said outer tube;

said shorter and smaller tubes being nested together in extended telescoping relationship;

interconnect means coupling each smaller tube with its next larger tube so that each smaller tube may be driven downwardly into the soil by a force exerted through its next larger tube,

means to disconnect said interconnect means when the smaller tube has been driven downwardly a distance equal to most of its extended length; and

means for extracting the extended tubes from the soil with an encased soil sample intact therein.

2. The device of claim 1 wherein a stabilizing fin assembly is provided to aid in maintaining vertical orientation of the sampler during its descent.

3. The device as defined in claim 1 wherein said outer tube comprises at least two sections to facilitate storage and transport.

4. The device as defined in claim 1 wherein the interconnect means includes outwardly biased links which extend laterally from the top edge of a tube and by which downward movement is communicated to cause downward movement of the tube.

5. The device as defined in claim 4 wherein the interconnect means and links engage the lower ends of progressively larger tubes so that each smaller tube is successively driven into the soil. 

1. A deep penetrating soil sampling device comprising: an elongate outer tube having a hollow interior; a plurality of shorter and smaller tubes within said outer tube; said shorter and smaller tubes being nested together in extended telescoping relationship; interconnect means coupling each smaller tube with its next larger tube so that each smaller tube may be driven downwardly into the soil by a force exerted through its next larger tube, means to disconnect said interconnect means when the smaller tube has been driven downwardly a distance equal to most of its extended length; and means for extracting the extended tubes from the soil with an encased soil sample intact therein.
 2. The device of claim 1 wherein a stabilizing fin assembly is provided to aid in maintaining vertical orientation of the sampler during its descent.
 3. The device as defined in claim 1 wherein said outer tube comprises at least two sections to facilitate storage and transport.
 4. The device as defined in claim 1 wherein the interconnect means includes outwardly biased links which extend laterally from the top edge of a tube and by which downward movement is communicated to cause downward movement of the tube.
 5. The device as defined in claim 4 wherein the interconnecT means and links engage the lower ends of progressively larger tubes so that each smaller tube is successively driven into the soil. 